Exercise machines having alternating reciprocating foot supports configured to traverse or travel about a closed path to simulate a striding, running, walking, and/or a climbing motion for the individual using the machine are well known in the art, and are commonly referred to as elliptical exercise machines or elliptical cross-trainers. In general, an elliptical or elliptical-type exercise machine comprises a pair of reciprocating foot supports designed to receive and support the feet of a user. Each reciprocating foot support has at least one end supported for rotational motion about a pivot point or pivot axis, with the other end supported in a manner configured to cause the reciprocating foot support to travel or traverse a closed path, such as a reciprocating elliptical or oblong path or other similar geometric outline. Therefore, upon operation of the exercise machine to rotate the proximal end, each reciprocating foot support is caused to travel or traverse the closed path. The reciprocating foot supports are configured to be out of phase with one another by 180° in order to simulate a proper and natural alternating stride motion. One example of an elliptical exercise machine is provided in U.S. Pat. No. 7,604,573, issue to Dalebout et al. on Oct. 20, 2009, which is expressly incorporated by reference herein.
An individual may utilize an elliptical or elliptical-type exercise machine by placing his or her feet onto the reciprocating foot supports. The individual may then actuate the exercise machine for any desired length of time to cause the reciprocating foot supports to repeatedly travel their respective closed paths, which action effectively results in a series of strides achieved by the individual to obtain exercise, with a low-impact advantage. An elliptical or elliptical-type machine may further comprise mechanisms or systems for increasing the resistance of the motion, and/or for varying the vertical elevation or height of the closed path. The resistance and elevation mechanisms or systems function when the individual is striding forward, and when the individual is driving in reverse to simulate walking backward. In addition, the reciprocating motion of the feet to achieve a series of strides may be complemented by a reciprocating movement of the arms, whether assisted by the exercise machine via a suitably configured mechanism or system, or unassisted.
The Dalebout et al. patent referenced above provides one example of an elliptical exercise machine wherein the driven components and the resistance components are located at the rear of the exercise machine. Additional examples of exercise machines with rear mounted components are provided in U.S. Pat. No. 6,875,160, issued to Watterson et al. on Apr. 5, 2005, and U.S. Pat. No. 7,425,188, issue to Ercanbrack et al. on Sep. 16, 2008. Alternatively, the driven components and resistance components may be mounted at the front of the exercise machine. Examples of such front mounted exercise machines include U.S. Pat. No. 6,019,710, issued to Dalebout et al. on Feb. 1, 2000, and U.S. Pat. No. 7,618,350, issued to Dalebout et al. on Nov. 17, 2009. Each of these patents is expressly incorporated by reference herein.
A typical closed path may comprise a generally horizontal outline having a longitudinal axis there through. Depending upon the exercise machine, a closed path may be many different sizes. As such, a particular measurement of interest to individuals with respect to an elliptical or elliptical-type exercise machine is “stride length.” A stride length is essentially a measurement of the distance separating the two furthest points along the longitudinal axis of the closed path. Therefore, upon actuation of the exercise machine, a single stride may be referred to as travel by the reciprocating foot support, and therefore the foot of a user, along the closed path from a first endpoint on the longitudinal axis of the closed path to a distal distant endpoint, also on the longitudinal axis. The stride and the upper resulting stride length provided by an exercise machine, although simulated and possibly modified, is comparable to a single stride achieved during natural and/or modified gait of an individual.
Many of the currently known elliptical exercise machines implement drive mechanisms incorporating a series of pulleys, belts and cables to translate the strides of the users of the elliptical exercise machines into rotational motion of the drive mechanisms. For example, in the Watterson et al. patent, the user's strides cause crank arms to rotate a flywheel that is connected to a drive by a belt to in turn rotate a weighted wheel to conserve momentum and maintain reciprocating displacement of the foot supports. In the Dalebout et al. '350 patent, reciprocating foot supports are connected to a drive assembly by crank arms to rotate the drive assembly, which then rotates a separate resistance assembly that is disposed below the drive assembly. As can be seen by these examples, the concatenation of multiple elements and assemblies can greatly increase the amount of space assumed by the rotating elements. Correspondingly, large covers are required to house the rotating elements to allow for safe operation of the elliptical exercise machines. For these reasons, a need exists for a new technology for transferring the motion of the user's strides to the driven elements of the resistance elements of elliptical exercise machines.